The biggest winner in Trump's decision to pull out of the Iran nuclear deal? Iranian hardliners

President Trump’s decision to walk away from the Iran nuclear agreement inflicts a damaging — perhaps fatal — blow to the prospect for evolutionary change in the Islamic Republic.

That leaves two possibilities, revolution or an increasingly repressive status quo.

Don’t hold your breath waiting for the revolution.

Much has been written about the damage Trump’s decision inflicts on U.S. alliances and America’s reputation for trustworthiness. Most of that is true. But the biggest loser is Iran’s moderate President Hassan Rouhani.

As Borzou Daragahi, a savvy reporter and analyst on Iran, points out in the Daily Beast, Rouhani’s opening to the United States was meant not only to prevent war and improve middle-class life by ending sanctions, but also to “cement the power of the more liberal wing of Tehran’s ruling elite, and marginalize hardliners.”

From the U.S. side, the nuclear deal was, in effect, President Obama’s bet that given an opening, Iran could evolve.

But in Iran, Rouhani is finding out that trying to reform a repressive system from the inside is just about the most treacherous political task imaginable. It’s hard enough if you hold unchallenged power. But Rouhani has attempted this feat with a large part of the establishment against him, and a supreme leader looking over his shoulder who is reflexively anti-American.

And now Trump has cut Rouhani’s feet out from under him. Even before Trump’s announcement last week, it was clear that the nuclear deal wasn’t delivering the economic benefits Rouhani had promised. He may have overpromised, but it wasn’t his fault that a lot of money got siphoned off to supporting Iranian proxies in Lebanon, Syria and Yemen. Now the economy is likely to get worse. At the same time, the Iranian president faces emboldened hardliners who insisted all along that Washington couldn’t be trusted.

It’s hard to imagine Iranians — even those who support Rouhani's efforts to build a kinder, gentler Islamic Republic — putting much trust in him or his allies now. This makes the hardliners stronger.

But does that lead to revolution? The logic motivating Trump and his new national security adviser, John Bolton, says it does — either because of increasing internal dissatisfaction or because the hardliners restart Iran’s nuclear program, leading to a military confrontation that they’ll lose. Maybe it just encourages a more intransigent, repressive Iran that now has another reason never to trust the United States.

There is no question that Iran faces severe domestic problems, including corruption, labor protests, a collapsing currency and capital flight. Instead of being aimed specifically at Rouhani, protests earlier this year were an indictment of the entire system. Unfortunately for Rouhani, as president he has to try to manage it all.

The clerical establishment retains substantial support, of course, but Iranians by and large seem past the point where they will offer unqualified backing to the government in times of crisis. Still, there are plenty of reasons why the mullahs are likely to remain in power.

Sanctions really aren’t very good at forcing regime change. As Stephen M. Walt points out in Foreign Policy, it hasn’t worked over many decades in Cuba or North Korea. Saddam Hussein was hurt by sanctions, but it took an invasion to overthrow him. If we take the protests in Iran early this year as a sign of budding revolution, the same logic would dictate that regime change is imminent in the United States, given the large protests against Trump.

Yes, sanctions will hurt Iran — but not that much. So no revolution is likely. That leaves aggrieved hardliners calling the shots. It’s hard to tell what they will do about the nuclear program. But Rouhani’s initial response to Trump, which Daragahi says appeared to be the result of a “painstakingly crafted consensus,” was quite cautious.

The elite will do what it takes to stay in power. As the recent military exchange with Israel in Syria indicates, they’re going to make the point that they won’t be pushed around.

Despite what Trump and Bolton seem to think, a big shove won’t bring down the Iranian government. It would take a catastrophic miscalculation in Tehran. The mullahs aren’t that stupid.